I would like to bump this topic as I'm suffering from similar but not the same problem related to igdumdim32.dll. I'm running FSX on Win7 Pro x64, DX10 preview, windowed mode. During many days of testing I managed to get stable simulation with good fps. I've got 2xRadeon7950 crossfired. My setup is multi monitor with 2 x 22" Dell running eyefinity display group. Now, my system is also equipped with internal GPU which is Intel HD 4000 series. I'm using it to run small 9' display for instruments.
CDT occurs only when I'm trying to drag undocked instrument window onto this small screen controlled by Intel HD 4000. It is 100% recurrent problem. My intel driver is updated to latest 10.18.10.3325 version. Previous version suffered the same problem.
Any ideas ?
I'm flying with standalone instruments (testing different frameworks, currently gaugebook) but it would be nice to have some nice GA gauges like realityxp. I need to solve this problem before I spend money on realityxp stuff.
Many thanks in advance.